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      • KCI등재

        응급실에 내원한 환자에서 어지럼증의 원인과 임상양상의 분석

        문원식,정경운,위준선,문정미,전병조,김용권,소정일,류진호,허탁,민용일 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

        Background: Recently, The number of patients who have been complaining of the vertigo or dizziness has been increasing due to rapid growth of elderly population and senile disease. The differentiation of dizzy patients is not familiar to most emergency physicians. This study was designed to differentiate true vertigo and to investigate the clinical difference among central vertigo, peripheral vertigo, and other causes of dizziness. Methods: The authors analyzed the cases of 237 dizzy patients who visited the emergency department of Chonnam University Hospital during the recent 2 years. For the base of dizziness, associated past illnesses, severity, nystagmus type, and the causes of central and peripheral vertigo. Results: Female patients were 142(59.9%) and male patients were 95(40.1%). The most common age group was the 6th decade. The origin of dizziness was classified as peripheral cause(25.3%), central cause(32.9%), and others(41.8%). As to nature of the dizziness, the rotatory sense was dominant in peripheral vertigo and the floating sense and blurred vision in central vertigo. Peripheral vertigo was triggered by position change of head and body, and central vertigo by the eye movement. Audiograms I showed that most patients with central vertigo had normal hearing, but 46.7% of thoswith peripheral vertigo had an abnormal hearing disturbance. Nystagmus was more prevalent in peripheral vertigo Conclusion: History taking and physical examination played an important role in the diagnosis of dizzy patients. An important part of the diagnosis of a dizzy patient could be to evaluate the peripheral origin, the central origin and others causes. Because central vertigo may be associated with a significant neurological pathology, spectral radiological studies, including MRI and CT, are mandatory to rule out a devastating brain lesion.

      • KCI등재후보

        급성 전벽 심근경색증 환자에서 심전도 하벽 유도 ST 절 하강의 임상적 의의

        최정현(Jeong Hyun Choi),전영주(Young Joo Jeon),정병기(Byung Ki Jung),최희만(Hee Man Choi),이중기(Choong Ki Lee),전재은(Jae Eun Jun),김항재(Hang Jae Kim),채성철(Shung Chull Chae),박의현(Wee Hyun Park) 대한내과학회 1991 대한내과학회지 Vol.40 No.3

        N/A To determine the significance of inferior ST segment depression during the early stages of acute transmural anterior myocardial infarction, we examined cardiac enzymes, in-hospital complications and indices of ST segment elevation in 51 patients presenting with acute anterior myocardial infarction. The patients were allocated to two electrocardiographic groups. Group I consisted of 19 patients (37%) with a 1 mm or more ST segment depression in at least two of leads II, III, and aVF, Group II consisted of 32 patients without this finding. Compared with group II, patients in group I had a higher peak creatine kinase and lactic dehydrogenase and experienced congestive heart failure, shock, arrhythmias requiring treatment, and death more frequently. Indices of ST segment elevation did not show a significant difference in both groups. The degree of inferior wall ST segment depression correlated weakly with the magnitude of the anterior ST segment elevation(r=0.63, p<0.01). Thus, the inferior ST depression during acute anterior infarction is a reliable marker of more extensive myocardial damage and an adverse hospital course. Such an inferior ST depression might reflect not only reciprocal change, but also ischemia in a remote inferior region.

      • KCI등재

        촉매-크래킹에 의한 나프타로부터 경질 올레핀 제조기술

        박용기,전종열,한상윤,김정리,이철위 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.5

        세계적으로 에틸렌 생산공장에서 배출되는 이산화탄소의 양은 매년 141백만 톤에 이르며, 석유화학산업에서 소비되는 전체 에너지 중 약 40%는 나프타 스팀크래킹에 사용된다. 이로인한 지구 온난화를 막기 위하여 에너지 효율 증대를 통하여 이산화탄소 배출양을 최소화할 수 있는 나프타 크래킹 기술개발이 시급하다. 또한 천연가스로부터 얻어지는 에틸렌의 양이 점점 증가하기 때문에 프로필렌/에틸렌 비를 증대하기 위한 연구가 필요한 실정이다. 그러므로 에틸렌과 프로필렌 수요를 맞추기 위한 thermal cracking의 대안으로 촉매를 이용한 크래킹기술이 시도되고 있다. 본 논문에서는 나프타로부터 에틸렌, 프로필렌 등과 같은 경질 올레핀 제조에 관하여 지난 수 년간 공개된 특허와 실용화 가능한 공정 기술을 소개하고자 한다. In the whole world, the amount of CO₂ emission from the ethylene plant is about 141 million tons per year, and currently about 40% of the energy in petrochemical industry is used for steam cracking of naphtha. So, global warming issues have stimulated the development of new cracking process of naphtha which can minimize CO₂ emission through the increase of energy efficiency. Also there is an effort to increase the ratio of propylene/ethylene in naphtha cracking since the natural gas cracker which can produce ethylene preferentially increases more and more. Therefore, catalytic cracking of naphtha has been studied as an alternative of thermal cracking to balance ethylene and propylene demand and to reduce CO₂ emission. This paper will review the various routes which have been investigated and applied over the past years, hut will focus particularly on the recently patented and commercially demonstrated processes for the production of lower olefins from naphtha.

      • SCISCIESCOPUS

        Prospective Clinical Trial of Corneal Reconstruction With Biomaterial-Free Cultured Oral Mucosal Epithelial Cell Sheets

        Kim, Yu Jeong,Lee, Hyun Ju,Ryu, Jin Suk,Kim, Yun Hee,Jeon, Saewha,Oh, Joo Youn,Choung, Ho Kyung,Khwarg, Sang In,Wee, Won Ryang,Kim, Mee Kum Masson Pub. USA 2018 Cornea Vol.37 No.1

        PURPOSE:: To investigate the efficacy and safety of transplantation with biomaterial-free cultured oral mucosal epithelial cell sheets (COMECs) for ocular reconstruction in subjects with total limbal stem cell deficiency. METHODS:: A prospective clinical trial (NCT02149732) was conducted in 8 subjects with total limbal stem cell deficiency after approval from the institutional review board of Seoul National University Hospital (H-0707-043-213) and the Ministry of Food and Drug Safety of Korea. COMECs were prepared in a culture system without the use of any temperature-sensitive polymers or carriers. The COMECs were transplanted without suture fixation. Four subjects underwent penetrating keratoplasty after stabilization of the COMEC transplant. Stable epithelialization, changes in visual acuity, and postoperative complications were evaluated for 6 months. Corneal cytokeratins (K) of 4 subjects who underwent penetrating keratoplasty were stained with an immunofluorescent agent. RESULTS:: The ocular surface was successfully reconstructed in 6 eyes. Complete stable epithelialization was achieved within a mean of 53.6 days. Visual improvement (≥2 lines) was achieved in 62.5% of the eyes. K12 (corneal phenotype), K4, and K13 (mucosal phenotype) were well expressed in grafts after keratoplasty, whereas K1, K8, and K19 were barely expressed. No ocular infections, local tumor formation, or remarkable systemic complications were observed. Ocular reconstruction using COMECs failed in 2 eyes, which had full symblepharon in 4 quadrants. CONCLUSIONS:: Transplanting biomaterial-free COMECs seems to be an efficient and safe procedure to reconstruct the ocular surface in patients who are completely limbal stem cell deficient without a full symblepharon.

      • KCI등재

        TransferJet 시스템의 성능분석

        박경원 ( Kyung Won Park ),위정욱 ( Jeong Wook Wee ),서정욱 ( Jeong Wook Seo ),전원기 ( Won Gi Jeon ) 한국항행학회 2012 韓國航行學會論文誌 Vol.16 No.5

        본 논문에서는 근접 전기유도 무선통신 시스템의 표준 기술인 TransferJet 시스템의 BER(Bit Error Ratio) 성능이 분석된다. TransferJet 시스템은 타 무선통신 시스템들과 비교해서 짧은 통신 범위(즉, 무선통신환경에서 높은 보안성), 더 적은 다중경로 왜곡, 그리고 높은 전송률을 제공하는 장점이 있다. 수신신호를 복조하기 위하여 TransferJet 수신단의 역확산기와 복조기에 연판정 결합(SC: soft-decision combining) 혹은 경판정 결합(HC:hard- decision combining)이 적용될 수 있다. 확산계수가 4이상인 경우에 SC 방식은 HC에 비하여 최소 2 dB의 SNR 이득을 제공한다. 또한, 모의실험 결과로부터, 3비트 양자화는 이중-정밀 부동소수점과 거의 동일한 성능을 제공하기 때문에 TransferJet 시스템에서 SC 방식에 대한 최적 양자화 비트는 3비트로 결론지을 수 있다. In this paper, BER(Bit Error Ratio) performances of the TransferJet system, which is the standard of a close proximity inductive wireless communication system, are presented and analyzed. Comparing to other wireless communication systems, the TransferJet system has some advantages such as short communication range(i.e., high security in the wireless communication environments), fewer effects of multipath distortion, and higher transmission rate. In order to demodulate the received signal, either SC(Soft-decision Combining) or HC(Hard-decision Combining) can apply to the despreader and demodulator of the receiver. When the spreading factor is more than 4, the SC scheme approximately has a minimum signal-to-noise ratio gain of 2 dB over the HC scheme. Moreover, from simulation results, we can conclude that the quantization bits of 3 bits are an optimum value for the SC scheme in the TransferJet system since the 3-bit quantization achieves nearly the performance as that attained by double-precision floating-point.

      • KCI등재

        CT 조영을 위한 금 코팅 리포솜의 제조

        위태인,전예원,조영재,조성근,하정,이정원,조선행,한희동,신병철,Wee, Tae In,Jeon, Ye Won,Cho, Young Jae,Cho, Sung Keun,Ha, Jeung,Lee, Jeong Won,Cho, Sun Hang,Han, Hee Dong,Shin, Byung Cheol 대한화학회 2013 대한화학회지 Vol.57 No.5

        암이나 혈관질환을 진단하기 위하여 영상의학기기들의 사용이 증가되고 있다. 영상의학기기 중 컴퓨터단층촬영(CT)은 가장 널리 이용되는 방법의 하나로서, CT를 하기 위해서는 조영제를 투여하여야 한다. 따라서, 본 연구에서는 리포솜의 표면에 금 입자를 코팅함으로써 조영제로 개발하고자 하였다. 금 입자를 코팅하기 위하여, 양이온성 리포솜을 제조하였고, 양이온성 리포솜의 표면에 음이온을 띄는 $Au^-$가 정전기적으로 코팅이 되게 하였다. 금 코팅 리포솜(GCL)의 크기는 $154.8{\pm}9.2$ nm 이었고, 표면전하는 $27{\pm}3.2$ mV 이었다. 리포솜의 형태는 주사전자현미경과 투과전자현미경으로 확인하였다. 리포솜 표면의 금 코팅 효율은 18% 였으며, MTT 분석을 한 결과, 금 코팅 과정에 대한 세포독성은 없었다. 그리고, 제조된 금 입자 코팅 리포솜을 CT로 촬영했을 경우 우수한 조영 효과를 나타냈다. 따라서 본 연구에서 제조된 GCL은 CT 조영제로서 다양한 혈관질환에 적용이 가능할 것이다. The use of medical imaging has been increased for diagnosis of cancer or vessel disease. Among the medical imaging, computed tomography (CT) is one of the popular methods, however, which should need administration of contrast medium. Therefore, we developed gold coated liposomes (GCL) as a contrast medium. To coat gold on the liposomal surface, positive charged liposomes was prepared and then negative $Au^-$ can coat on the liposomal surface by electronic interaction. The size of GCL was $154.8{\pm}9.2$ nm and surface charge was $27{\pm}3.2$ mV, respectively. The morphology of GCL was confirmed by electron microscopy (SEM) and transmission electron microscopy (TEM). The coating efficiency of gold was 18%. Chemical procedure for gold coating on liposomal surface was not toxic for cell cytotoxicity by MTT assay. Finally, we demonstrated attractive CT image for GCL. Taken together, the GCL would be useful for various vessel related disease as a contrast medium.

      • Ninjurin1 Deficiency Attenuates Susceptibility of Experimental Autoimmune Encephalomyelitis in Mice

        Ahn, Bum Ju,Le, Hoang,Shin, Min Wook,Bae, Sung-Jin,Lee, Eun Ji,Wee, Hee-Jun,Cha, Jong-Ho,Lee, Hyo-Jong,Lee, Hye Shin,Kim, Jeong Hun,Kim, Chang-Yeon,Seo, Ji Hae,Lo, Eng H.,Jeon, Sejin,Lee, Mi-Ni,Oh, Go American Society for Biochemistry and Molecular Bi 2014 The Journal of biological chemistry Vol.289 No.6

        <P>Ninjurin1 is a homotypic adhesion molecule that contributes to leukocyte trafficking in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, <I>in vivo</I> gene deficiency animal studies have not yet been done. Here, we constructed Ninjurin1 knock-out (KO) mice and investigated the role of Ninjurin1 on leukocyte trafficking under inflammation conditions such as EAE and endotoxin-induced uveitis. Ninjurin1 KO mice attenuated EAE susceptibility by reducing leukocyte recruitment into the injury regions of the spinal cord and showed less adhesion of leukocytes on inflamed retinal vessels in endotoxin-induced uveitis mice. Moreover, the administration of a custom-made antibody (Ab<SUB>26–37</SUB>) targeting the Ninjurin1 binding domain ameliorated the EAE symptoms, showing the contribution of its adhesion activity to leukocyte trafficking. In addition, we addressed the transendothelial migration (TEM) activity of bone marrow-derived macrophages and Raw264.7 cells according to the expression level of Ninjurin1. TEM activity was decreased in Ninjurin1 KO bone marrow-derived macrophages and siNinj1 Raw264.7 cells. Consistent with this, GFP-tagged mNinj1-overexpressing Raw264.7 cells increased their TEM activity. Taken together, we have clarified the contribution of Ninjurin1 to leukocyte trafficking <I>in vivo</I> and delineated its direct functions to TEM, emphasizing Ninjurin1 as a beneficial therapeutic target against inflammatory diseases such as multiple sclerosis.</P>

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